This invention relates to a releasable fastener. The fastener of the invention is particularly useful to mount components to a plate member such as a piece of sheet metal in the engine compartment of a motor vehicle.
Conventional fasteners for attaching a component to a plate member are shown in FIGS. 1 and 2. In FIG. 1, fastener 100 includes a pin 110 and an isolation grommet 120 that cooperate to fasten component 140 to plate member 150. Pin 110 is fixedly mounted to the plate member 150 via a threaded hole formed in the plate member. The pin includes a pin main body 111 having a protruding flange 112 at a head portion 113 thereof. Grommet 120, which is inserted into a mounting aperture 144 formed in a wall of the component 140, includes cylinder member 122 having an exterior flange 124 for engaging a surface 142 of the component, and an interior peripheral surface 126 for engaging the flange 112 of the pin. The head of the pin 110 is inserted into the grommet 120 whereby the protruding portion of flange 112 engages the peripheral surface 126 of the grommet resulting in an attached condition between the component and the plate member. As shown in FIG. 1, the pin is mounted to the plate member, and the grommet is inserted in a mounting aperture formed in the component. An alternate configuration, where the pin and grommet positions are reversed, is shown in FIG. 2.
Referring to FIG. 2, fastener 200 includes pin 210 and isolation grommet 220. Pin 210 is formed as an integral part of component 240 (e.g. by injection molding) and includes a pin main body 211 having a flange 212 at a head portion thereof. By first inserting the grommet 220 into a mounting aperture 244 formed in a wall of the plate member, and subsequently inserting the head of the pin into the grommet 220, an attached condition between the component and the plate member is realized when a protruding portion of flange 212 engages a peripheral surface 226 formed on an inner surface of the grommet. Components 140, 240 can be various parts such as an air filter housing or an intake pipe, which are adapted to be mounted in the engine compartment of a motor vehicle.
With each of the prior art fasteners shown in FIGS. 1 and 2, prior to inserting the pin into the grommet, the method of using the fasteners includes the additional assembly step of inserting an isolator grommet into a aperture formed in one of the parts. Furthermore, once a pin is inserted into the receiving portion of a grommet, the pin is not readily removable without likely causing damage to the fastener (e.g., damaging the grommet). Finally, the fastener illustrated in FIG. 1 involves the added step and the added expense of forming a threaded hole in the plate member in order to fixedly mount the pin thereto.
Accordingly, it would be advantageous to provide a fastener comprising an integrated isolator grommet such that the added step of inserting an isolator grommet into an aperture in one of the parts can be eliminated. It would also be advantageous to provide a fastener that obviates the need to form threaded holes and that can be easily unfastened so that attached parts can be easily unattached.